Europa (moon)
Europa is a large moon of the planet Jupiter. It is a little smaller than Earth's Moon and it is the sixth-largest moon in the Solar System.
 Europa has a white surface | |||||||||
| Discovery | |||||||||
|---|---|---|---|---|---|---|---|---|---|
| Discovered by | Galileo Galilei Simon Marius | ||||||||
| Discovery date | 8 January 1610 | ||||||||
| Designations | |||||||||
| Jupiter II | |||||||||
| Adjectives | Europan | ||||||||
| Orbital characteristics[2] | |||||||||
| Epoch 8 January 2004 | |||||||||
| Periapsis | 664862 km[a] | ||||||||
| Apoapsis | 676938 km[b] | ||||||||
Mean orbit radius | 670900 km[1] | ||||||||
| Eccentricity | 0.009[1] | ||||||||
| 3.551181 d[1] | |||||||||
Average orbital speed | 13.740 km/s[1] | ||||||||
| Inclination | 0.470° (to Jupiter's equator) 1.791° (to the ecliptic)[1] | ||||||||
| Satellite of | Jupiter | ||||||||
| Physical characteristics | |||||||||
Mean radius | 1560.8±0.5 km (0.245 Earths)[3] | ||||||||
| 3.09×107 km2 (0.061 Earths)[c] | |||||||||
| Volume | 1.593×1010 km3 (0.015 Earths)[d] | ||||||||
| Mass | (4.799844±0.000013)×1022 kg (0.008 Earths)[3] | ||||||||
Mean density | 3.013±0.005 g/cm3[3] | ||||||||
| 1.314 m/s2 (0.134 g)[e] | |||||||||
| 0.346±0.005[4] (estimate) | |||||||||
| 2.025 km/s[f] | |||||||||
| Synchronous | |||||||||
| 0.1°[5] | |||||||||
| Albedo | 0.67 ± 0.03[3] | ||||||||
| |||||||||
| 5.29 (opposition)[3] | |||||||||
| Atmosphere | |||||||||
Surface pressure | 0.1 µPa (10−12 bar)[6] | ||||||||
Europa's diameter is about 3000 kilometers. It probably has an iron core, and a thin atmosphere of mostly oxygen. The surface is icy and very smooth. There are not a lot of craters, but there are some cracks and lines.
Scientists believe that there is a liquid ocean under the surface, and that it is kept warm by tidal heating.[7] In other words, heat from tidal flexing (Jupiter's strong gravitational pull on Europa) makes it warm. Europa certainly has a lot of water.[8]
The moon Europa was found by Simon Marius in December 1609. Galileo Galilei first saw the moon in January 1610 (he did not know Marius had found it). Simon Marius was the one who had the idea of the name 'Europa'.
Europa is named after a princess from Greek mythology who became the first queen of Crete.
References
Notes
Other websites
- Europa Archived 2011-05-20 at the Wayback Machine
